


Little (Big) Black Box

by Acetate (DramaLama)



Category: Haikyuu!!
Genre: Alternate Universe - College/University, Established Relationship, M/M
Language: English
Status: Completed
Published: 2016-04-07
Updated: 2016-04-07
Packaged: 2018-05-31 19:48:41
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,383
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6485251
Author URL: https://archiveofourown.org/users/DramaLama/pseuds/Acetate
Summary: <blockquote class="userstuff">
              <p>Oikawa hands him the black box, forcing him to come to terms with the fact that he’s just agreed to wear a tiny black thong for four hours, for Oikawa. Regret has already had made itself home in the pit of his stomach.</p>
            </blockquote>





	Little (Big) Black Box

 

Iwaizumi figures that he’s quite well versed in the language of Oikawa Tooru’s many, many, _many_ facial expressions at this point in his life so when his long-time friend, captain and—although he’ll deny it—boyfriend appears on his doorstep at the ass crack of dawn sporting grin number three. He does the smart thing by slamming the door shut in his face and turning back around. Unfortunately, he’d forgotten that he’d given Oikawa a key to his apartment just last week (a decision he was quickly coming to regret with the amount of times Oikawa seemed to magically appear just as he was about to shower or sleep) so the door banging open came entirely as a surprise to him. Much like the arms that wrapped themselves around his torso.

He reasons that the elbow jab into Oikawa’s stomach was wholly deserved and stares down at him, unimpressed.

Oikawa laughs and Iwaizumi doesn’t want to categorise the look that’s sent his way as adoring but that’s exactly what it is. He has to look away least he end up imitating the way Oikawa’s eyes crinkle at the corners and the way his smile lights up his whole face.

“What do you want so early in the morning—“He starts, unable to finish the sentence because he’s somehow ended up sprawled across Oikawa on the hardwood floor.

Unamused is the expression he directs at him. There’s also annoyance in the mixture, a dash of anger and just the tiniest hint of arousal. Which he squashes down on as quickly as possible through the power imagination—Ushijima’s face alone being enough to stop any and all erections for him.

“I can’t come to see my Iwa-chan in the mornings?” Oikawa asks, feigning innocence (Iwaizumi knows that look and it screams trouble).

“The last time you showed up in the mornings, you brought a butt plug with you and tried to convince me to wear it during practice.”

Oikawa had the decency to look sheepish but not fully apologetic—or regretful—at what he’d done.

“We had fun that night though.”

Stubbornness had Iwaizumi denying that with a vengeance but Oikawa wasn’t fooled if that sly smile was anything to go by. Rather, Iwaizumi felt him shift their positions so he could slide his leg in between his thighs and torture his cock into half hardness.

He repaid the favour by biting into Oikawa’s shoulder, very hard.

The surprised yelp left him feeling very pleased with himself. The twitch of his cock when Oikawa whined, “Iwa-chan,” low and far too close to his ear was very much unappreciated.

When they’d started dating a couple years or so ago, the details being quite sketchy—although Oikawa swears that it was on a Friday—because everyone else agrees that they’d started dating the moment five year old Oikawa had slapped Iwaizumi across the face and then proceeded to cry a tsunami of tears because he’d accidentally hurt “princess Iwa-chan,” it hadn’t taken Oikawa long at all to discover most of Iwaizumi’s weaknesses. The same could be applied to him but that was mainly because Oikawa had happily told them to him. In graphic and unnecessary detail, but one of those weaknesses had to do with biting, anywhere and everywhere. It drove Oikawa insane with desire and Iwaizumi had happily taken advantage of that, except for right now, when one of Iwaizumi’s weaknesses consisted of Oikawa coming into contact with his ear. Whether that was biting, licking or even moaning near it, Iwaizumi loathed that it could initiate such an intense reaction out of him and he hated the fact that he’d come to love it so much.

The first incident had been during an afternoon practice match. He’d returned from his jog around the university’s large field to start volleyball practice. Half the team had been changing into their uniforms in the change rooms while the other half were out setting up equipment and checking line-ups for the upcoming tournament in summer.

He’d had one leg perched up on a silver bench so he could pull up his shin guards when Oikawa—and his fan club—had shown up in a whirlwind of screaming and cheering, the latter taking position up on the seats while Oikawa strolled past him to get changed.

He’d looked up, ready to lecture the captain on turning up late—for the hundredth time—when Oikawa promptly leant towards him and whispered a very low, “Sorry I’m late Iwa-chan,” right into his ear. It effectively stopped any sound from coming out of his mouth and left him blinking owlishly at Oikawa’s retreating figure (the full body flush had appeared a minute later).

Oikawa had left him so distracted that he’d managed to mess up nearly all his serves, a handful of receives and even managed to launch a spike straight into the ceiling. The coach had pulled him off to question him on his health but the moment he’d spotted Oikawa’s smug ass grin from across the room he’d assured the man that he was perfectly okay and demonstrated that by launching his next serve straight into the back of Oikawa’s head. Getting kicked off the court for the rest of the day had been well worth it.

“Stop ignoring me.” Oikawa whines against his ear, ripping him out of his reverie. Helpless for the beat of a second before he manages to snap out of his trance, because getting caught up in Oikawa’s pace is what he doesn’t want to happen first thing in the morning.

“I ignore you when you’re being stupid. Which is ninety five percentage of the time.” He snaps, attempting to push himself up off of Oikawa. It’s a worthless effort though because he’s not really even trying.

Oikawa nuzzles against his neck, aware that he’s won—by a thread—for now. “The other five percent?” He asks.

“I want to punch you in the face.”

“Iwa-chan!”

There’s a dumb smirk spreading across his face and he’s glad Oikawa is too preoccupied with burying his face into his neck to see it (no need to stroke his massive ego).

“You were supposed to say something kinky.”

He rolls his eyes at the exact same moment that Oikawa decides to swipe his tongue, slowly, up Iwaizumi’s neck in punishment. The arch of his spine is an entirely unconscious act on his part and so is the low groan that Oikawa drags out of his throat.

“You want to know what I want to do to you fifty percent of the time?”

“I really don’t.” He growls out.

“I want to fuck you, and the other fifty percent—“

“I said I didn’t want to know asshole, don’t make me punch you.”

“I want you to fuck me.”

Now? His mind supplies, unhelpfully.

“Yeah, now, right here.”

It takes him a long, drawn out minute to realise that he’d accidentally spoken that out loud. Traitorous brain.   

“Have class.” He offers up weakly. Resolve dissolving by the heartbeat as he pushes himself up on his hands and knees and catches Oikawa’s smug smile and the slow lick of his lips. Like a fucking cat.

“In three hours. We have the same morning lecture, Iwa-chan or did you forget already?” Oikawa asks, cupping his erection through the thin cotton of the pants he wore.

He should’ve known Oikawa had had something planned. The asshole always did when smile number seven appeared. That’s not what goes through his mind though when Oikawa simultaneously spreads his legs and slides a hand into his pants to rub against his cock.

 

“Stop falling alseep!”

“Shut up, you’re too loud.”

“That’s no way to treat the boyfriend whose ass you just came into without wearing a condom.”

He buries his head deeper into the cushions, face beat red. They’d somehow managed to navigate their way into the lounge—the bedroom being much too far—before tearing each other’s clothes off. A feat in and of itself with how much Oikawa seemed to want to do it on the floor. Fingers stroking against his prostate had the setter much more compliant though.

“I said I was sorry.” He grumbles, scowling when Oikawa gives his bare ass a slap. “Stop that.”

Oikawa does it again just to spite him.

There’s a heavy weight pressing down on his back and he doesn’t need to turn over to know that Oikawa has hopped up to sit on top of him. He makes no move to shove him off—it’s tempting though.

“My ass is sore.”

“Congratulations.”

“Don’t be mean, Iwa-chan.” Oikawa says, while grinding his flaccid cock into the cleft of Iwaizumi’s ass.

“If you try to shove your dick in there. I will rip it off.”

“I thought we discussed your form of dirty talk, Iwa-chan. The threat of bodily harm does not turn me on.”

Iwaizumi grumbles into the cushion, intent on going back to sleep. Unfortunately, Oikawa seems determined on denying him that right.

“Iwa-chan.” He begins.

Iwaizumi answers in the form of another grumble, quieter though because he really is falling asleep. There’s a kiss pressed against the nape of his neck, feather light and gentle and it makes him even sleepier.

“My ass _is_ really sore.”

He turns his head so that he can just spot the side of Oikawa’s face out of his peripheral vision. There’s no cheeky grin or secretive smile on his face. He looks as drowsy as Iwaizumi feels and that has Iwaizumi worried that he’s somehow managed to hurt Oikawa. Guilt gnaws at his insides and he twists around so that Oikawa and he are lying chest to chest.

“Sorry.” Is the first thing that leaves his mouth. “Are you okay? Do you need anything?” Comes next.

The first time Oikawa and he had had sex, it had been a complete disaster. They’d awkwardly fumbled their way into Oikawa’s bed, lips and hands everywhere. Iwaizumi had managed to slam his head into the wall when he tried to get Oikawa to straddle him, which had Oikawa laughing for a solid five minutes and then apologising for another five when Iwaizumi had tried to leave from sheer embarrassment. After that, everything had gone by fine until they reached the actual fucking and realised that not enough spit—because neither had any lube on them—had been used. Oikawa had shed actual tears from the pain and Iwaizumi had ben guilt ridden for weeks afterwards but now he always made sure to prepare Oikawa properly before entering him.

“Make it up to me.” Oikawa says.

His initial reaction is to say no—force of habit—but he asks how instead.

Oikawa taps a slim finger against his chin, deep in thought before his face lights up and he grins.

“You can’t refuse.”

Suspicion enters his gaze and he pulls back a bit, weary of what Oikawa might ask of him.

“Promise?”

“What are you going ask?”

“You have to promise me first.”

“Then no.”

“Iwa-chan!” Oikawa whines, pressing his face against the middle of Iwaizumi’s chest. “It’s a rule!”

That fucking rule. The only way Iwaizumi had been able to absolve himself of his guilt for hurting Oikawa was by establishing that fucking rule. The one where the other person was allowed to ask for one thing if they’d been hurt during sex. It was a dumb fucking rule that they’d literally enforced once after that first time because Iwazumi had made certain that he’d never subject Oikawa to that ever again.    

He was partially regretting that now though. Damn Oikawa and his memory.

“I promise I won’t say no.” He grinds out in defeat.

Oikawa’s happy smile manages to leave him feeling both overjoyed for having put it there and also terrified of what he wants Iwaizumi to do.

“Close your eyes.”

“No.” He says while squeezing both eyes shut. It makes Oikawa chuckle.

The weight lifts off his chest, there’s a soft rustling noise and the sound of a bag being unzipped before Oikawa’s weight returns to settle on top of him.

“Open.”

He squints one eye open and then the other.

There’s a little black box in Oikawa’s hands and he’s reaching for the pillow next to Oikawa before he’s even aware of it. Before Oikawa has time to react he’s slapped the setter upside the head with it. Twice.

“It’s not what you think it is!” Oikawa exclaims, hopping off the couch to protect his hair from further dishevelment.

Iwaizumi shoots him a very unimpressed stare. “I don’t want to know what’s in there. I’m not doing it.”

“You promised!” Oikawa accuses, pointing a finger in his face. He glares at it.

“It’s not even that bad and you promised…” Oikawa trails off, clearly disappointed in him.

“Open it.” He snaps, hating everything.

Oikawa brightens up immediately. The faker. He opens the box.

“No.”

“Iwa-chan!”

“Where did you even get that?!”

“The internet, Iwa-chan. Come on now, I know you idolise cavemen but I also know you know how online shopping works.”

“No.”

“It’ll make me really happy.”

“Seeing your reflection in store windows makes you happy.”

Oikawa shrugs, unashamed. “This’ll make me happier.”

“You wear it then.”

“I will if you want me too.” That makes Iwaizumi pause. “But only after you wear it for me.” And then resume scowling.

“Send that thing back where it came from Oikawa, or so help me I’ll send you flying back with it.”

Oikawa sighs dramatically, sprawling himself across Iwaizumi’s chest. Or at least he tries to. He ends up curled on his side, wincing instead and Iwaizumi has lost the battle.

“One hour.”

“Twenty four.”

“Do you want to die?”

Silence. “Four.”

Iwaizumi thinks it over. “Deal.”

Oikawa hands him the black box, forcing him to come to terms with the fact that he’s just agreed to wear a tiny black thong for four hours, for Oikawa. Regret has already had made itself home in the pit of his stomach.

 

He’s going through plan sixty four of his mental list, titled ‘Ways to kill Oikawa Tooru’ when he realises that in the four hour time frame, volleyball practice just about fits inside. He’s completely forgotten that they have practice at noon on Wednesdays and comes up with another twenty five ways to kill Oikawa Tooru.

The moment he’d gotten on his bike an hour previous. Regret had filled his whole being. It was a wonder they hadn’t crashed because he’d had the biggest and most uncomfortable wedgie of his life. Oikawa behind him, whining that it wasn’t fair that he hadn’t been able to see it hadn’t helped either. 

Walking to their first class was just as nightmarish as the ride to campus had been. He’d been constantly plagued by the urge to pull the thong out of his ass and insanely paranoid that everyone walking past them _knew_. Sitting three rows away from a whinging Oikawa had brought much needed satisfaction and peace for him. He’d almost forgotten about the damn thing, until he’d stood up and spotted Oikawa waving at him sporting that dumb smile of his.

Ignoring him until practice—because that was impossible or else he would’ve done that too—worked for the most part and nothing really happened until they were sorted into teams for a practice match. Oikawa’s first serve really should’ve alerted him to what the dumbass had in store. It hadn’t even been one of his crazy ones and yet he’d still managed to serve it straight into the back of Iwaizumi’s head, just hard enough to bring him to his knees.

“Oops, sorry, sorry Iwa-chan. I got distracted by something in front of me.”

“You need me to fix your eyesight for you, dumbass?” Iwaizumi growled, getting to his feet.

That was fight number one. Fight number two started when he’d scored a point against three blockers and Oikawa came up to him for a high five. He’d turned back around get ready for the next set when a hard slap against his ass stopped him, and several other people in their tracks.

“Nice one, Iwa-ch—”

Four people had had to break that one up.

Fight three occurred in the change rooms after Oikawa had hooked a finger under the waistband of his shorts and tugged hard enough to get a peek at the black material that was fast ruining Iwaizumi’s life.  

“Oh!” He’d exclaimed in delight. “Let’s—”

That day, the team declared Oikawa a hardcore masochist and updated his social media details—who used the vice captain’s birthday as a password of all things—accordingly.

“Don’t you have class at five?” Iwaizumi asks, slinging his bag over one shoulder while making his way over his bike parked in the lot.

“Nope, class was cancelled because of the oral test next week, but more importantly look at this Iwa-chan!” Oikawa cries out, shoving his phone right up in Iwaizumi’s unamused face.

“I can’t see anything if you put it this close to my face, dumbass.” He aims a hard kick into Oikawa’s side which, in turn reminds him that there is a thin piece of fabric wedged up his ass crack.

“That hurt!”

“Good.”

Oikawa pouts but holds the phone a bit further away from Iwaizumi so he can see.

 _Oikawa-Iwaizumi Tooru._  
_World’s sexiest setter and husband to the world’s finest ace._  
_Hardcore Masochist. Ask Iwa-chan._  
  
“Look at all these blurry photos of me! I never put these up!” 

Iwaizumi squeezes his eyes shut and counts backwards from ten. It helps lessen his desire to commit murder, but not by much.  When he’s certain that he won’t do something regretful—like strangle Oikawa—he opens his mouth to speak.

“When did we get married?”

Oikawa is still complaining about the photos but he looks up when Iwaizumi speaks, brows knitted together in thought.

“I thought _you_ changed that.”

“Do you want me to hit you?”

“What did we say about dirty talk that turns me on, Iwa-chan. The threat of bodily harm—”

“Oikawa.” He growls out.

“See? _That’s_ how you do it.”

When Iwaizumi remains silent, conveying death through his eyes. Oikawa reluctantly relents and agrees that he’ll change it back to normal even though he wasn’t the one who’d changed it in the first place. Iwaizumi is positive he’ll see something worse before the day is over though. Knowing his fucking teammates and Oikawa being a sore loser.

Which he demonstrates the moment they reach Iwaizumi’s apartment (although there’s enough of Oikawa’s fucking things in there that he secretly calls it theirs). He doesn’t even have enough time to make it to his bedroom before Oikawa has him cornered against the kitchen counter.

“Iwa-chan.” He sings because he fucking knows that Iwaizumi didn’t have the balls to change out of them in the change rooms that afternoon. Too afraid that someone would see them. So the initial four hour deal had actually extended to five.

“I’m changing.”

“Okay.”

The agreement catches him off guard. He’d been so ready to argue back—physically if need be—that he’s shocked into silence. His steps are cautious as he by-passes a smiling Oikawa into the bedroom. He wants to demand that whatever Oikawa has planned it won’t work and he doesn’t realise he’s been standing in front of the wardrobe for a straight five minutes until he catches Oikawa strolling in wearing just a pair of sweats.

“I’m changing.” He says.

“You said that five minute ago, Iwa-chan. Kindaichi styles his hair faster than you getting changed.”

“I’m changing.” He repeats like a broke record.

He hears Oikawa humming for a few seconds before he feels strong arms wrap around his torso. “So you say.” He whispers. “But I don’t see any undressing happening.”

“Get out.” He growls, weak at the knees.

Oikawa hums again and buries his face into Iwaizumi’s neck, inhaling.

“That’s disgusting.” He mumbles and feels Oikawa’s shoulders shake in response.

“You do it too.”

He’s about to deny that he does when Oikawa grasps his crotch firmly in one hand. Iwaizumi flinches because the other hand has somehow managed to sneak its way up his shirt to tease a nipple into stiffness. He lets out a low groan.

“You just had to tell me that you wanted to show me, Iwa-chan. You’re so bad at conveying what you want but then again,” Oikawa chuckles. “I love that about you, it’s cute.”

“You’re dead.”

“Love you too.” Is accompanied by languid kisses against his neck that have him arching his neck back.

“Show me. I had to wait five hours you know. I’m practically dying here.”

“Do it yourself if you want to see so badly.”

Oikawa bites his neck for the span of two seconds before spinning Iwaizumi around and dropping to his knees in front of him. “Nope. You will.”

And then Oikawa proceeds to lick his cock through his fucking pants. It’s not at all appealing, Iwaizumi tells himself even as he begins to feel himself hardening through the cotton of his shorts (fuck him for not choosing jeans today).

“Stop that.” He groans out.

Oikawa answers by pressing a finger into the back of his pants, right where the material digs into his asshole. He’s grateful for the wardrobe at his back because right now that is the only thing keeping him upright. He wants to kick Oikawa in the face and kiss him at the same time. It’s a disaster.

“Oikawa.”

Oikawa stares up at him and the intensity of that gaze is the tipping point for Iwaizumi. He lets out a frustrated sigh and hooks two fingers into the waistband of his pants. Oikawa pulls back enough for him to wrench the shorts down in one quick swoop.

“We need to work on your stripping skills Iwa-chan. That wasn’t nearly as sexy as I imagined it would be.”

Iwaizumi huffs but Oikawa’s stare has him averting his gaze, embarrassed.

“Turn around for me?”

Fucking Oikawa and his fucking voice. He turns around, mumbling curses the whole way. It’s the sharp intact of breath behind him that has him pausing.

“What is it, asshole?”

That seems to be the queue for Oikawa to put his hands on Iwaizumi’s ass, spreading them.

“Well, I can see yours, Iwa-chan.”

“You!” Iwaizumi flushes a deep red and tries to twist back around, fully intent on punching Oikawa into next Wednesday for being such an embarrassing idiot. Oikawa stops him though, or more specifically, his tongue up Iwaizumi’s ass does.

“I’m going to kill you.”

Oikawa’s hum makes him shudder and he slams his head into the wardrobe, defeated.

He can’t remember how they end up sprawled across the bed—Oikawa’s complaining most likely—but they do. He’s reaching for the thong, trying to tug it off when Oikawa stops him with a heady kiss.

“Keep it on for a little bit longer, I want to try something.”

It’s that dangerous look on Oikawa’s face. Number seventy two or something. It’s the one that Iwaizumi finds so hard to say no to because it makes him feel light headed and dizzy. So he doesn’t. He agrees and find out exactly why Oikawa wants them on.

Apparently, underwear fetish had to be added to Oikawa’s list of weaknesses after today. Iwaizumi doesn’t even notice when he’d ended up on top of Oikawa, lubricated cock pressing insistently against his hole.  

Oikawa stares up at him with hooded eyes, waiting and expectant. He doesn’t push or prod at Iwaizumi to sink down onto his cock. It’s honestly the only time Oikawa is that quiet (he’s a sleep talker) and it always leaves Iwaizumi feeling completely bare. Like Oikawa can see through every single thought running through his head at this exact moment. Some days it’s unsettling but other days—like today—it drives him crazy.

He pushes down, hard and fast. The spread and burn well worth the look of surprise that flashes across Oikawa’s face.

They’re both silent and unmoving for a few minutes before Oikawa bursts out laughing.

“S-stop that, you idiot. Don’t move!” Iwaizumi hunches forwards, shoving his face into Oikawa’s shaking chest.

“Your hole is totally twitching right now, Iwa-chan. It’s really hot.”

“Fuck you. Go to hell.”

“Love you too.”

The sex is ruthless and Oikawa can’t seem to stop staring at his clothed crotch every few minutes.

It continues well past an hour because Oikawa seems insistent on getting him to cum as many times as he is physically capable of. This reaches a point where Iwaizumi slaps him with a pillow exclaiming that it feels fucking gross being stuck in wet underwear for so long. Oikawa replies by thrusting harder into him.

 

“You have a problem.”

“That’s mean Iwa-chan. It’s called love!”

“No, I’m pretty sure it’s a problem.”

Oikawa hugs him tighter in response and makes some weird dog noise.

“I did not make a weird dog noise!”

Iwaizumi snorts and twists around so that he’s face to face with Oikawa. Who glances away, sheepish.

“What?” is accompanied by a wide yawn.

“You know when I said my ass really hurt this morning…”

“It didn’t. I know.”

“What, how?!” Oikawa exclaims, sitting up abruptly. The blanket gets pulled off of both of them in process.

“Are you stupid? I know when you’re actually in pain, stupid.”

“You can’t ask if I’m stupid and then call me stupid Iwa-chan! That’s not nice!”

“So loud.” Iwaizumi mutters, shoving his head under a pillow. He mumbles something that Oikawa doesn’t catch.

“What?” Oikawa asks against his ear. Fucking Oikawa.

“I said I knew because you fucking jumped onto the bike—”

“Oh, yeah—”

“—and played volleyball like you always do, dumbass. Get off me so I can sleep.”

The bed dips and there’s a warm body pressing against his side. The blanket covers his back next.

“So then, why did you—”

“What, I can’t do shit for my boyfriend?”

The blanket is rudely pulled off of him a second time.

“What did you just say?”

“Goodnight.”

“It’s evening, Iwa-chan. I didn’t fuck you that hard that it would affect your sense of time but more importantly repeat that for me. Please.”

“You better put your phone away or I’ll throw it out the window, Oikawa.”

“Repeat it, Iwa-chan. Please!”

 

 


End file.
